Acid digestion demonstration (WeDID)

Abstract

Acid digestion process development began at the Hanford Site in 1972 with a beaker of laboratory acid and progressed through laboratory and pilot-scale development culminating in the Radioactive Acid Digestion Test Unit (RADTU). The RADTU was operational from 1977 through 1982 and processed over 5,000 kg of synthetic and combustible waste forms from Hanford Site operations. It routinely reacted plastics, wood, paper, cloth, ion-exchange resins, metals, and solvents. Operation of RADTU routinely gave volume reductions of 100:1 for most plastics and other combustibles. The residue was inert and was disposed of both as generated and after application of other immobilization techniques, such as calcination, addition to glass, and cement addition. The system was designed to accommodate offgas surges from highly reactive nitrated organics and successfully demonstrated that capability. The system was designed and operated under very stringent safety standards. The Weapons Destruction Integrated Demonstration (WeDID) program required a technology that could dispose of an assortment of weapon components, such as complex electronics, neutron generators, thermal batteries, plastics, cases, cables, and others. A program objective was to recycle and reuse materials wherever possible, but many unique components would need to be rendered inactive, inert, and suitable for disposal under current environmental laws. Acid digestion technology was a key candidate for treating many of the above components; it provided accepted technology for treatment of chemicals and elements that have posed disposal difficulties designated by the US Environmental Protection Agency (EPA).